10 years in the making

"Great spirits have always encountered opposition from mediocre minds. The mediocre mind is incapable of understanding the man who refuses to bow blindly to conventional prejudices and chooses instead to express his opinions courageously and honestly."

--- Albert Einstein

The latest olfactometer not only measures the odour concentration at the source where the odour is released, but also evaluates the odour sensation at the location where the odour is perceived. The dilution-to-threshold technique has limited its application to some strength odour samples. The direct evaluation of the odour attributes in the laboratory is suitable for ambient odour monitoring. This new approach extends the current technology and completes the missing link in odour measurement. It also provides better detection limit for investigating odours in the field than chemical analysis.

At the turn of the millennium, odour concentration measurement standards have been published in many countries after more than half a century of research. It is no doubt that the standardisation has reduced the large variation in odour analysis results. But, the overall performance from the odour testing laboratory in the past 10 years is a long way from industry expectations. Anecdotal evidence suggested that most olfactometer systems have yet to demonstrate compliance with the published standards.

Experience gained through thousands of odour samples tested on a mass flow controller based olfactometer has been a rich resource for our research team to specifically target the shortfall of the existing technology. Our professional conscience is the motivation to make improvements which could enhance stable and consistent instrumental performance over long periods of time.

Olfactometer technique is the cornerstone of odour science. We have to measure the odour in order to develop effective solution, to evaluate the efficiency of the odour abatement technique and to assess the odour impact from the operation in question. The erroneous measurement results could have severe consequences and lead to the wrong conclusion.

Odour only exists if one can smell it. The human nose is the ultimate detector. Olfactometer is the interface for the panellist to evaluate the odour sensation in a controlled environment. DynaScent is the latest generation olfactometer to measure the odour in all its aspects. To design the optimum gas dilution system, the aerodynamic performance is modelled using the latest computational fluid dynamics. The DynaScent has also been redesigned to better suit the ergonomic needs of the panellists.

The truth is in the detail. Over the past 10 years, the features of DynaScent have been systematically and gradually enhanced in many areas. The latest improvements now include multiple olfactometer systems with one database and Bluetooth wireless connectivity. Other improvements are:

Minimising the backlash movement in driving the valves.

Flushing out the dead air in the system at the beginning of the testing.

Coating the sniffing cups to remove the metallic smell.

Reducing the noise level.

Improving the flushing sequence.

Introducing triangle presentation mode.

Presenting the sample ‘as perceived’ without dilution.

These improvements have led to a much more reliable testing result in our testing laboratory. While a variation of ±100% is acceptable in the European standard, our laboratory has consistently reported the variation within ±66% on a binary presentation mode. With the introduction of triangle presentation mode, the variation of ±33% could be achieved.

The ongoing research and development has made some significant progresses in achieving objective odour measurement. It is possible that the perceived odour can be brought back to the laboratory without losing the perceived odour sensation. The availability of odourich measurement fulfils a gap in measuring the ambient odour. The industry and stakeholder can apply the technique to resolve a community odour complaint. The Regulatory Authority can replace a field inspector with the technique when monitoring the environment at a property boundary.